Apparatus for treating chocolate or the like



May 12, 1953 W-WGWWEYGVAND ETA]. 2,638,329

APPARATUS FOR TREATING CHOCOLATE on THE LIKE Filed June 5, 1947 4 Sheets-Sheet 1 "WWW I NVENTORS 014% 44nd farlnflwmzszm May 12, 1953 w. s. WEYGAND ETALY 2,633,329

APPARATUS FOR TREATING CHOCOLATE OR THE LIKE Filed June 5. 1947 f 4 Sheets-Sheet 3 g If ' 50 16 MM 51:: 7 ,|u"""' 'M/mum 'T:Irfm :11 g

67 rm 5 5F 55 7.1

m j e 96 a9 jg} ATTORNEY May 12, 1953 w. G. WEYGAND ETAL 2,638,329

APPARATUS FOR TREATING CHOCOLATE'OR THE LIKE 4 Sheets-Sheet 4 Filed June 5, 1947 NW R w. 0 x m M m M We M Patented May 12, 1953 eleasezs TANG QR THE IiI'KE "3 Claims. (01. 25931418) I This l v ntib relates tn-epeemti'us a e tfiea tnf' ehoeulate or the likey and m re sped tel a ehgeolate melting and tempering kettle of meted 'character. 3

In the candy and other industries, :prepam, tiim of chocolate usually i vel'ves melting end se -called tempering .operati'ohs, bind the necessary apparatus for such treatment apresehts a twefoild pmmem of considerable magnitude. In the first place, the maten al itself is difil'c'ult to and especially far the preparation bf 5a desirably smooth, 'homgeneeus prbductz that is unimpaired :by any depa'htune tram :enitziearl p g; esm qconditi ns of itemneretuee or the like: the .SE'QQIIQ place, high etamlards er esamtatieh mnet e mtiefied, as in gleamin theveeuinment. after each use, and also epneizefiting an tam-nation .ef the. ehee' zlate itselfi a More specifically, or example, eizeat have must e taken t amid a. erehee ines and et under Sat e nd tiens of temperature he eheqelate made to adher to the :81; we of e kettle we, mat ng adequate eg te imme me whe esr f heat r 11tsi.,.e he kettle t interior port ons of the .Ineleanmgth eeeleme aft r ach :batch h beer; reee ed, it i he heu t 'te remove selidified heeo1at eepee 1;? item cor er and crevices, yet h ppe eain t I t makes it mperativ to ha he aecumulet ens iorflr sidue n any partloith epnamtn v, er neteueh deposits ma actually i coe- .r

tact with vsu sequent hetehes oi the m 11; is qually essential to mit v irl t ,DQS b1. 9i lcentaminatine the ehotmate, not 401113 with r en matter thatjinight be fl pbeited nm the a. Wphere Qt otherwise. but al o s on, a

r parades bf metal such as might qqme iron: the mixing machinery. Sinee the nature 0i hecelavte mixe i bract c y impes ible, by tiny r in'ary b rvat on, to esce a h that Q 321.- tami atipn is pcpurring' and s nce the spoiling r therensamt rymture of small 1* 'tatiehfs of ,choeoiate in the a paratus "i giiafly ard t receghize, extraordihary precautions muet' he ta-ke to prevent these dimeuitie; ahd jiiah y mic; t pes or heati g and xing ipmeht eii he'r (10 not pei ih t such pre'cautipps Or require mqtdimte .a-mbum; of time and. efieet to effectpate them, Y hee rdingiy, an im orta t bject f the present 1 intention is to prev-me apparatus of the iih'arae eir fle cr be wherein t :e Dv problems o Qperation and 'sahitatioh are efiective y overcame, afford ng heat ng and thixifle apparatus *vf wh requires a minimum of attentitvh and is easy w and the elem, and ve p izmits s neri results in operations such as meltir gand temper.- ieea v Qther e vme e epe fic e i ets are t e qiie a kettle and agitator structure of novel ghai: eater, whe ein the marine pa ca he steadi y disassembled ea ily leane and t pr vid uch appa atus hav ng nte -Wed c per me ns whereby the in rim Walk ar eonti ously scraped durin t e n i e (me-ration, s a to perm t efleetive heat twis e fa ilitate s rrin and prevent lumpin 9r e er undesira le har-- acteristics in the treated iehecelete.

A further object isto spre sle 1& w arran ement of the kettle, including a cover struetuxe f r it, which ziaeilitate r oleae ee and also p vents t a cumulation at neeeess -h e e eeitsi however smail, of selidihed c n olete Al k j t. is the provision, .zin :such dev ees, p 1m? pnov'ed outlet r draw nfi the m lted chocolate, such means bein p efieet vely anitary haracter, protected from irt; et e ily cleaned, and at the same time amply s ited, 0 its intended purpose. Y

Another and Particularly important objeet is {m provide a novel and efiieient apparatus fe heating and agitating a mass of eh QQ 1 er- {i'ahged to avoid any possibility-of eontaminatirgg the latter with grease er oil from the mach ne y, an to avoid anydir'ect exposure ;0f the :choeolate ti) small mechanical parts which might gbecpgn e mosene "and hmken .off ahd thus be ignolmii Q other-wise embedded in the mass. Additiona eh;- jee'ts are t0 provide structurally improved agitate mg means, "light in weight, simple in confi uratie-n aim feasyto handle; and a navel arranger ment or the driving medhanism, readily EM-lees sible ahd yet adequately separated from the in.- tri'e r 0f the kettle. Still further objects. are the pro ision of greater ineehani'cal efliaien'cy in the stirring operation, remarkable uniiormity and improved thermal 'eflieiehc'y in heating the bbdh or ehocdlate, and greater conveniende in various other respects, e. g. in'contrdl or .eupervisidn .of the supply of water and steam t0 the heating system, 'ahd likewise in eflecting the initial installation aiid connection :of the a paratus.

Ah additional objeet is to prdride improizemehts --s atisfyihg one of more of the foregei-ng Objects, in apparatus useful for Lprocessihg of other feed materials or the like.

To these and other ends, including objects ,he'reinafter abpa'rnt er cither wise ineidehtazl to the use of the deseeieee apparatus, a presently preferred embodiment of the invention is shown in the accompanying drawings and set forth in the following description, by way of example, to illustrate the several novel features and combinations, and the principles underlying them.

Referring to the drawings:

Figs. 1 and 2 are respectively elevational and plan views of the kettle, on a reduced scale relative to the remaining figures;

Fig. 3 is a vertical section of the kettle, on a.

central plane but with certain internal parts shown in elevation;

Fig. 4 is a section on line 4-4 of Fig. 3;

Fig. 5 is an enlarged fragmentary section on line 5-5 of Fig. 3;

Fig. 6 is a section on line 6-6 of Fig. 3;

Fig. 7 is an elevational view, taken from line 1-1 of Fig. 3, of the agitator and scraper structure. w th the tank in central vertical section;

Fig. 8 is a section on line 8-3 of Fig. 3.

Fig. 9 is an enlarged elevation of the drain valve, closed; and I Figs. 10 and 11 are sections on line Ill-Ill of Fig. 9, with the valve respectively open and closed.

Referring to the drawings and particularly to Figs. 1 and 2, the illustrated apparatus comprises an external housing Ill, in the form of an'upright cylinder advantageously made of heavy sheet metal, and a cover H, likewise of sheet metal. The device is supported in a level position, by four (4) independently adjustable legs I2, preferably with sufficient space from the floor to allow the latter to be cleaned easily at any time.

Turning now to Figs. 3 to 8, it is seen that the kettle comprises an upright inner vessel generally designated [4 and having a cylindrical outer wall 15 and a flat bottom iE-from which a central tubular column I! projects upwardly within the wall I5 and preferably to a point well above it. The wall [5 has a shorter radius than the housing In so as to provide a water jacketing space l8 between them, and the upper end of the space [8 is closed by a H) integral with or welded to the wall I5 and seated on the inwardly flanged upper edge of the housing [0, from which the vessel M is thus hung. The wall l5, bottom [6 and central column 11 define the chocolate receiving vessel and are preferably welded or otherwise constructed so as to afford a smooth, continuous interior surface without flanges, shoulders or sharp inside corners, it being noted that the corners between the bottom and the concentric v cylindrical surfaces l5 and H are appropriately rounded, as shown at 20, 2!. This entire structure, for example, may be made of polished stainless steel sheet, making it still easier to clean'and also facilitating both the scraping operation in the chocolate mass and the transfer of heat through the walls.

The housing {0 has a relatively heavy, horizontal partition 23 spaced below-the bottom N5 of the vessel to provide a further water jacketing region 24, and an internal tubular column 25 is mounted, as by a flanged base 26, to extend upwardly from the partition and within the column IT. The concentric columns are spaced to provide an annular water jacketing region 21, which is in full and open communication with the horizontal jacket 2-3, as is also the outer jacket l8. The jacketed column structure is internally traversed, i. e. through the tubular element 25, by a central, coaxial shaft30, journaled heavy, horizontal flange near its lower end in a suitable roller bearing 3| in the base 26, and near its upper end in a like roller bearing 32 secured within the column H. The upper bearing 32 is disposed well below the top of the column H, and rests on the upper edge of the column 25, *whichis correspondingly shorter; the bearing also has a cover 33 fastened in sealed relation to the interior of the column H, and closely surrounding the shaft. Thus it is effectively impossible for lubricant in the bearing or on the shaft below to work its way up to and over the top of the column IT. The combination of the cover 33, the case for the bearing 32 and the column 25 may also provide some central support for the vessel M, on the partition 23. k

The upper end of the shaft 30 above the bearing is splined or squared to receive the congruently shaped central opening of a collar-like head 35 which can thus be slid down over the shaft for rotation by the latter. The shaft carries a threaded stud 36, upon which a nut 38 may be screwed, to engage a correspondingly apertured end plate 39 secured on the head 35, i. e. so as to lock the latter in place.

The inner collar portion 40 of the head 35 extends within the tubular column H, and the head also has an outer skirt 4!, depending for a considerable distance down the outside of the column. Agitator and scraper members for the interior of the vessel [4 are attached to the head 35 as described below, but it will now be more fully appreciated that by virtue of the central column arrangement and the instrumentalities in and around it, there is no effective communication between any lubricant-carrying portion of the shaft 33 and the interior of the kettle l4, and the water jacketing spaces are entirely sealed from both the shaft and the kettle. Thus not only is contamination of the material in'the kettle positively prevented but a1- so, chiefly because of the skirt 4 i, there is no opportunity for chocolate. to be splashed or carried into the driving'parts.

, Although other forms of agitator or scraper structure may be mounted on the head 35 for continuousor intermittent displacement by the shaft, and although more or less stirring elements may be provided in some cases, the illustrated machine advantageously includes a pair of oppositely disposed agitating and scraping assemblies, generally designated 45. Since these assemblies are conveniently identical in structure, except in being mounted on diametrically opposite sides of the head 35, particular description of one of them will suffice for reference to both.

As shown, the assembly comprises a pair of upright members or blades N6, 41 (see particularly Figs. 3, 4, 5 and 7), respectively near the wall (5 and the cylindrical surface of the column 11. The vertical blades are connected by transverse members such as the blade 48 near the bottom is of the vessel, and spaced, intermediate stirring blades 49, 50, the uppermost blade 50 being also spaced considerably below the top of the kettle and likewise beneath the surface of the body of chocolate when the kettle is full. The inner vertical member 41 projects integrally from a coextensive supporting element 52 which has the shapeof a fragment of a cylinder concentric with the column ll, tapering in its circular di mension from a large are at the top to a small one at the bottom. r The part5? also has an extended portion .54 at its upper end shaped to flit bhe outer surface of the skirt M (of :iihc head :35.) where it is fastened by nuts on threaded studsbli projecting from the skirt. Although other type of construction may be employed, the entire agitator assembly of the members Allwith lzhe supporting member 52 and its extension 54 ma advantageously :be .a single, integral castin c. .9-

of aluminum or 20171181 .l-ightmetal. ,l lorrcirrlfiorcement. additional, integral flanges or ribs may be provided, as at .51, 58 between the blade 4?! and various localities of the -member :52.

As the shaft or rotates the headofi both of the agitator assemblies :hung from the latter are swung around the vessel, 1. e. in the "wide an- ,mrlar space between the outer wall 415 and the column ll. Each assembly has its raises some what spaced .from the surfaces of :the vessel and carries supplemental structure rlor continuously scraping the latter. in accordance with :a urtheir and presently preferred feature of the in? vention, the scraping means is removably pivoted or hinged to the agitator frame, Thus for instance, an outer .edge portion of the :blade .46

has a vertical, undercut groove constituting a long cylindrical or tubular recess opening through a co-extensiye, axially extending slot .61 toward the {outer wall 15 of the vessel, the slot preferably facing the wall at an acute angle, as shown in Figs. 4 and 5.

Supported by {the groove 60 are a pluralitvof scraper elements .63 arranged in tandem, each comprising :a hat or (blade-like portion having :a central opening to iacilitate passage of the blade through the chocolate (see also the .similarly identified openings in the bottom blades .hereinbelow described, Figs. ,4 landb) ,and an em larged base or head 5'! of elongated cylindrical shape to fit the tubular groove .60 with .the blade portion projecting. In this ,way eachscraper 6.3 is hinged to the agitator assembly, the base 61'! constituting a pin that can be slid endwise into the pin receivinggroove fill. The spacing of the member 46 Irom the wall 5-5 is preferabl such that the scrapers meet the latter at a relatively sharp acute angle, .while the hinge arrangement, wherein the slot 6'! is considerably wider than the blade 63, permits "the scraper to .turn orrrock as necessary for more perfectly following the contour of the wall. a single long scraper may be provided, a more freely pivoted support and a better scraping operat-ion' have been achieved by using a tandem, i. -e. "end-to cnd series of scraper elements, for example four, as shown.

The inner blade 3-! has an identical pin receiving groove i-ll to hold -a similar series of scraper elements 32 in removable, hinged relation by their pin-like bases 13, for scraping engagement with *the "outer surface of the central column '17. The same kind of arrangement is also provided to scrape =the bottom P6 of the yessol, including a plurality of scraper elements 15, c. g. three in tandem, having pin-like pontions- 16 removably he'ld in corresponding horizontal grooves l at the-edge of the cross-member 18. Thus both of the agitator assemblies 45 are equipped with pivoted blades on all three sides, andas the-assemblies revolve in the ketitle :to stir 'the chocolate, all of the surfaces are zefiectlvely and .coniiinuouslyscraped. If -.dcsin,ed, the lower end :of :each groove 6G, M and one end of the groove if! may have stop means, such as .a :small inwardly projectingstud -'(.not.sho.wn) -.to help hold ath'e rscraper blades on place, especially Although in some instances 8 when the agitators are being in the kettle.

Various driving and connecting parts of the machine are disposed in the space below the partition 23, to which access may be had through a plurality of large openings in the housing 1:0, each normally closed by a removable louvered plate so. The lower end or the shaft 30 v(Figs. 3 and 8) carries a worm gear 82. engaged by a worm 84 on a horizontal shaft 85 which in turn carries a pulley 86 to be driven by a belt 8?! from a suitable source of power such as an electric motor 89 (Fig. 8). The described gearing is enclosed in a housing 90 depending from the partition 23 and filled with lubricating oil to a predetermined level by means of an oil filler conduit 9-! including an upstanding, removably capped filler pipe 92 behind one of-the access plates 80. The jacketing space 18, 24, 21 may be filled with water through an inlet conduit 94' that opens through the partition 23 and that has a, valve 95 and extends through a further pipe 96 to a source of water supply, not shown. To drain the water at desired times, a similar conduit 98 opens into the. jacketi-ng space at the partition and extends through a valve 99 to a T I100 which may have its lower branch piped to a suitable waste conduit, likewise not shown. An over-flow pipe M62 is disposed in the jacketing space l8, for example in the position shown in Figs. 5 and 6, slightly forward of the plane of Fig. 3, where it is also shown, for completeness. The upper, open end of the pipe I02 thus G ll rmines the level to which water will rise in the jacket, and its lower end connects with the drain T Hm. Since the space 21 in the central column 'is closed at the top, a small vent pipe 1,04 extends up into it, opening at the same level ,as the over-flow pipe Hi2, and also having a lower portion 105, connecting with the drain T 180, as shown in Figs. 3, 6 and 8.

Among various heating means that may be used, a particularly convenient arrangement comprises a spiral coil of tubing Hll, having a multiplicity of turns generally concentric with the vessel andits central column and disposed in the j cketing space 24- The .co l is thus held by appropriate supports 1 ll between the 'hQfifiQm wall I 6 of the vessel and the partition 13.. A

steam supply conduit .l l2 including a Valve .413

opens ,into one .end .of the coil, and other or inner .end communicates with an output pipe .ll 5 .110 discharge steam, through a suitable radial mp Althou h it be understood chat othersteain-icontrolling in trumentalities may be m l yed, in jact preferably including thermostatic mean vfor maintaining .the steam or the water or indeed the interior the home :at selected temperature, the present illustration has been simplified by showin only the in le valve 1.13 for a ju ting z -hesunplyiofsieam-tothe heating coil Ml). lit will Ibo i'flfilifid that {the several valves 35, so and #113 are conveniently so anran ed :tbat their operating handles project outside the housin in, flor iroa-dy access.

,fl' or observation of zthe water level in the :iackoting ;-spaces asight window 5%? (Eigs. -1=and 53) is pronided :in also ahocisl'ng *iill near fiche 13 p, preferably sodisposedath-at the dorsal of the open,- ings of thepipes in: and EHM "is midway between the upper .andlloweinedgesof the window. 'wherlathe iacketis properly :filled, the water level should :be seen at:theicenterlof-thelfield of view, itbeing remembered st-l'iat the over fiowpipe M2 is actually somewhat spaced from the window (Fig. rather than across it as might appear from Fig. 3 alone.

For withdrawal of melted chocolate, a short, cylindrical conduit I22 opens into the vessel I4 and projects through the outer housing III. The lowermost region of the inner surface of the conduit I22 lies in the plane of the bottom I6 of the vessel and the joint between the conduit and the vessel wall is made to be entirely smooth and without projecting shoulders or depressions, to avoid entrapment of the chocolate material. Referring to Figs. 9-10 as well as Figs. 2-5, the outer end of the'conduit carries a flange I24 apertured in exact conformity with the conduit and having a vertical face across which a gate I25 is disposed to slide, the gate being pivoted at I26, at one side of the flange. A peripheral region I21 of the outer face of the gate is tapered or wedge-shaped, and the flange carries a stud. I28 having a large notch I29 correspondingly tapered at its outer wall (i. c. with the same small angle). Thus when the gate, operated by its handle I30, has been swung clockwise from open position through the partially open relation of Figs. 3 and 5, and is approaching the closed position of Figs. 2, l, 9 and 10, the wedge-shaped portion I2! is forced into the notch I23, in a direction lengthwise thereof. The gate is thus brought to a stop and the wedging action of the notch on the gate face I2! presses and holds the plane surface of the gate very firmly against the flange I24.

The described assembly thus constitutes a gate valve, of simple but peculiarly effective form, to close the drain spout. To open the valve and permit discharge of fiuid or semifluid material from the vessel, the handle is swung upwardly, sliding the gate I25 across the flange seat I24, uncovering the opening in the latter. The contents of the vessel I4 may then flow easily into a suitable collecting container placed under the opening, the conduit I22 projecting sufficiently, as shown, to permit ready location of such container. It will be particularly noted that the valve structure is'of completely sanitary character, in that there is a minimum of mechanism, and the single moving part is fully exposed and accessible for cleaning. There are no crevices or other localities to accumulate a deposit of chocolate and the face of the flange I24, over which the chocolate runs on discharge, is fully covered and protected by the gate member I25 during periods of closure. At the same time, by virtue of the described wedging and locking action of the stud I28 on the gate a remarkably tight and drip-proof closure is obtained for the spout, yet it can be easily opened to a wide extent for removal of the melted product.

The cover II for the vessel is preferably pressed or otherwise fashioned from a single piece of stainless steel or like sheet material and includes an upstanding cylindrical, recessed portion I33 to-house the upper end of the drive shaft 30, the collar 35 and associated parts. The cover is circular in plan and has a short depending skirt I34 fitting snugly around the top outer edge of the housing I0. At one side the cover has a segment-shaped opening I35 surrounded by a flange I36 struck up from the sheet metal and provided with a supplemental sheet metal cover I31 of like shape, which is skirted to fit over the flange I36 and which is hinged by ears at the ends of its straight side I38 so that it may be raised for filling the vessel, inspection of con- 8 tents or addition of further material. It will be noted that the cover structure, particularly as made of smooth sheet material, has a correspondingly smooth surface facing the interior of the kettle I4, without crevices or other regions where chocolate might become inaccessibly lodged. The flanged filling opening I35 is similarly free of such crevices; the simple structure throughout facilitates cleaning, and for the latter purpose the entire cover assembly can be readily removed simply by sliding it up against its frictional grip around the housing wall II].

The apparatus has been found convenient to install, simple to use and remarkably efiicient in operation. Piping connections for water, steam and water drainage are readily effected beneath the raised open bottom of the housing I0, and likewise electrical connection to the motor 89, while subsequent access to these and other mechanical parts is easily obtained as described hereinabove. At the same time, all of the mechanism, piping and the like is completely shielded from access by the chocolate, thus avoiding deposit of the latter on difficultly cleaned mechanical parts.

In operation the agitating and scraping assemblies, mounted on the head 35 are inserted in the vessel over the end of the shaft 30, and secured by tightening the single nut 38. The cover is applied and the desired quantity of chocolate and other ingredients, if any, may be inserted through the opening I35. Assuming that the jacketing spaces I8, 22 and 21 have been filled with water tothe level of the pipes I02 and I04, and assuming that steam of the desired temperature and pressure has been admitted to the heating coil IIIJ, the apparatus is ready for operation. At the outset or other desired stage in the melting processes, the drive mechanism may be started, turning the agitator assemblies, clockwise as seen in Figs. 4 and 5, for example at a rate of about 20 R. P. M. The heater element raises the temperature of the water in the jacketing spaces to the desired value, and since those spaces not only surround the sides and bottom of the vessel but also adjoin the upstanding cylindrical column II, a particularly rapid and effective transfer of heat to the chocolate is effected. The central location of the heater elements provides a balanced, uniform heating effect in both the outer and inner verti cal jackets, and the relatively thin-walled structure of the vessel greatly facilitates heat transfer to the chocolate, in contrast to prior types of iron kettles. Since the drain conduit I22 traverses the jacketing space, the material in it is also effectively heated and kept fluid so that when the operation on one batch is completed, the kettle contents can be readily drawn off.

As explained above, the agitator assemblies not only stir the mass but their blades 33, l5, l2, scrape practically the entirety of the side wall, bottom and column wall as the drive shaft turns. This action promotes the desired mixing and uniformity of the material and also greatly facilitates heat transfer, by preventing the accumulation of a layer of poorly heat conducting chocolate on the interior surfaces of the kettle. The arrangement of multiple blades hinged to the support is self-aligning and effects good scraping contact with the surfaces at all times; and the angular relation of the blades is such that the mass of chocolate ahead of the moving assembly, particularly adjacent either wall or the bottom,

mamas effectively forces the blade against the surfaneto "be scraped.

lence and agitation of the chocolate mass,' in

that the latter is continuously" forced through an opening somewhat like a shallow funnel) smaller than the radial dimension; of. the kettle between the outer wall and the: central column.

The corresponding angular arrangement of the transverse blades 49, 59 (see Fig. 9?) oooperatesfin exactly similar fashion toward effecting, turbulence and thus vigorous agitation of thelmass traversed by the described assemblies. The scraper blades may be made of stainless steel slightly less hard than the walls of the vessel so as to avoid scoring or roughening the polished wall surfaces.

As indicated hereinahove, all chocolate-exposed parts are such that they may be very easily taken apart and cleaned. Thus the cover II is removed, the nut 38 unscrewed and the entire stirring structure simply lifted out as a unit. The simple, smooth and massive configuration of the agitators, their lightness of Weight and the open nature of the grooves 60, l0, l1, greatly facilitate scrubbing operations on these parts, and similar characteristics are of corresponding advantage in cleaning the smooth interior of the vessel It, the drain spout and its valve, and if necessary to wash it, the outside of the housing It]. If desired, the agitator assemblies 45 can be unbolted from the head 35, although ordinarily they need not be. At the same time, the structure is exceptionally sturdy, the support of the vessel It being such that it can be built to have a capacity of 1200 pounds or moreof chocolate. Finally, as also explained, the arrangements including the disposition of driving parts below the kettle and the shielding function of the column ll, avoid the use of stufiing boxes and amply protect the chocolate against contamination with oil, grease, small metal parts, or the like, from the mechanism.

Although the described machine is of outstanding and indeed unique advantage for its stated operations in the treatment of chocolate for the manufacture of confectionery and the like, it will now be appreciated that various features and combinations may be applied to other apparatus or for other uses, e. g. as in the melting, mixing or processing of other viscous or thermoplastic materials, and especially in handling and treating other food compositions which are fluid or semi-fluid and which require a high standard of sanitation.

It is to be understood that the invention is not limited to the specific structures herein shown and described, but may be embodied in other forms without departure from its spirit as defined from the following claims.

We claim:

1. In apparatus of the character described, in combination, a vessel having a smooth interior surface comprising a cylindrical outer wall, a

concentric cylindrical column and a bottom between them, agitator structure for the region between the column and the outer wall, said agitator structure including a frame having vertical members respectively adjacent the Wall and column and a horizontal member adjacent the bottom, supplemental stirring members connecting said upright members, and scraper blades removably hinged at the edges of said upright members and lower member. for scraping the cylindrical wall, central column. and bottom respectively, a shaft traversing the central column and means removably securing the inner one cf said upright mambers to a portion of the shaft above the column, said blades and members including parts freely separable upcn sliding the blades longitudinally relative to the members, for providing the aforesaid removably hinged attachment of the blades to the members.

2. In apparatus of the character described, in combination, a vessel having a smooth interior surface, comprising a cylindrical outer wall, a concentric cylindrical columnand a bottom between them, agitator structure for the region between the column and the outer wall, movable along a predetermined path, said agitator structure including a frame having vertical members respectively adjacent the wall and column and a horizontal lower member adjacent the bottom, supplemental stirring members connecting said upright members, and scraper blades removably hinged at the edges of said upright members and lower member and adapted to project forwardly of the agitator structure in its path for simultaneous scraping engagement with the wall, the column and the bottom at an acute angle, the said upright members and lower member having blade-like configurations disposed to be in alignment with the scraper blades when the latter are in the aforesaid engagement with the outer wall, the column and the bottom so that said upright members and lower member and the scraper blades associated therewith, when moving cooperate in plough-like engagement with material in the vessel to cause the pressure of said material to hold the blades against the outer wall, the central column and the bottom.

3. In a vessel of annular configuration about a vertical axis with inner and outer concentric vertical surfaces and a connecting bottom, an agitator structure comprising a frame having a portion to be connected to a shaft at the axis for revolving the frame about said axis, said frame comprising upright members to be disposed respectively adjacent the inner and outer vertical surfaces defining said annular configuration and a lower horizontal member disposed adjacent the bottom of the vessel between said upright members and vertically spaced intermediate horizontal members joining said upright members, both said vertical and at least two of said horizontal members having blade-like configurations tilted at cooperating acute angles to the annular path of the frame to provide a shallow funnellike opening through which material in the vessel is forced as the frame is revolved about the aforesaid axis, said frame having undercut grooves along the outer edges of the upright members and the lower edge of the lower horizontal member and said agitator structure including scraper blade members with elongated, enlarged bases removably disposed in said grooves, thereby pivotally mounting the blade members to project obliquely from the frame for scraping engagement respectively with the inner and outer vertical surfaces of the annular vessel and with the bottom thereof.

WILLIAM G. WEYGAND. JACK SWEN'DSEN.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Muser July 6, 1886 Walter Mar. 6, 1900 Fawkes May 26, 1903 Taylor Sept. 1, 1903 Hollstein Sept. 28, 1915 Bourell Aug. 22, 1916 Santicola Mar. 20, 1917 Stout Aug. 10, 1920 Hartshorn Mar. 14, 1925 Camp Jan. 31, 1928 Morrow Aug. 2, 1932 Number 12 Name Date Curd Aug. 9, 1932 Keck Aug. 1, 1933 Corn et a1. May 1, 1934 Bigelow et a1 Mar. 26, 1935 Lewis et a1. June 1, 1937 Parcell May 23, 1939 Derleth July 18, 1939 Valentine May 21, 1940 Holmen July 16, 1940 Rapisarda Sept. 16, 1941 Wagner Mar. 10, 1942 Mojonner et a1 Apr. 21, 1942 Fraser Dec. 17, 1946 

